My iPhone 7 had issues and I had done encrypted backups using iTunes. Apple gave me new iPhone as replacement. When I restored from iTunes backup, my Google Authenticator is blank.

I have lot of sites configured and I am not sure what to do now. Any help? I did download the backup codes from Google and it gave 10 codes. How do I used the codes for other sites like coinbase, Amazon, etc.?

There are alternative two-factor auth apps out there that provide the same functionality as Google Authenticator and allow you to sync your two-factor codes to your other mobile devices. Authy (authy.com) is one such app. I switched from Google Authenticator to Authy just for this reason: I lost all my two-factor codes when I upgraded my iPhone. (I have no vested interest nor personal connection to the Authy app nor company that develops it.)
– jefe2000Dec 6 '17 at 16:01

2 Answers
2

If Google Authenticator is anything like Microsoft's authenticator, it is tied to the device, not just the account. This is how Google knows it's actually you because you are using a device that you have in your posssession (it wouldn't be secure if you could use it on any device anywhere).

When you restored, you restored the Authenticator tied to your old device and since the devices are technically different, nothing comes up. This is expected behavior as the app intentionally doesn’t include data in an encrypted backup to allow your tokens to transfer with the rest of the device backup like Apple keychains and health data and other iOS saved passwords and settings.

As if you'll always have the same device and never wipe/restore it. What a horrible auth system that creates more security vulnerabilities than it prevents as users flood the support systems on sites with queries about being locked out of accounts!
– sudoFeb 14 '18 at 4:11

Unfortunately, Google Authenticator doesn’t offer a restore option. Not all services offer backup codes. If you have backup codes from Google you can use them only to restore an access to your Google account. If you haven’t downloaded backup codes from other services you should restore an access to your accounts with the help of Support Team. Contact the Support Team of each service you protect with Google Authenticator, they will help you to restore an access to your accounts. After this, you’ll be able to issue tokens on your new iPhone.